path: root/fs/ext4/ext4.h
diff options
authorZheng Liu <wenqing.lz@taobao.com>2012-07-09 16:29:29 -0400
committerTheodore Ts'o <tytso@mit.edu>2012-07-09 16:29:29 -0400
commit729f52c6be51013c9268e5fc85acbc1091286fdb (patch)
treec3e8a6348ef23fcf15797b9f68905ec666ec43f8 /fs/ext4/ext4.h
parentfbe104942d3ff44f6802e8e4a3fbf267c1fb9ac4 (diff)
ext4: add a new nolock flag in ext4_map_blocks
EXT4_GET_BLOCKS_NO_LOCK flag is added to indicate that we don't need to acquire i_data_sem lock in ext4_map_blocks. Meanwhile, it changes ext4_get_block() to not start a new journal because when we do a overwrite dio, there is no any metadata that needs to be modified. We define a new function called ext4_get_block_write_nolock, which is used in dio overwrite nolock. In this function, it doesn't try to acquire i_data_sem lock and doesn't start a new journal as it does a lookup. CC: Tao Ma <tm@tao.ma> CC: Eric Sandeen <sandeen@redhat.com> CC: Robin Dong <hao.bigrat@gmail.com> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 01434f25917..4a49f8225d0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -571,6 +571,8 @@ enum {
/* Request will not result in inode size update (user for fallocate) */
#define EXT4_GET_BLOCKS_KEEP_SIZE 0x0080
+ /* Do not take i_data_sem locking in ext4_map_blocks */
+#define EXT4_GET_BLOCKS_NO_LOCK 0x0100
* Flags used by ext4_free_blocks